Improved lifting-jack



UNITED STATES PATENT OFFICE.

IMPROVED LIFTlNG-JACK.

Specification forming part of Letters Patent No. 51,381, dated Dec( mber5, 1665.

To all lwhom 'it may concern:

Be it known that I, ALFRED WooDwoETH, ot North White Oreek, in thecounty of Washin gton and State of New York, have invented a new anduseful Improvementin Lifting-Jacks; and I do hereby delcare that thefollowing is a full, clear, andexact description thereof', which willenable those skilled in the art to make and use the same, referencebeing had to the accompanying drawings, forming part ot' thisspecification, in which- Figure 1 is a longitudinal vertical section otalifting-jack with my invention applied thereto, taken in the plane ofthe line x a', Fig. 2. Fig. 2 is a top view of the same with the headot` the rack-bar removed.

Similar letters of reference indicate corresponding parts.

My invention consists in the employment or use of a spiral springlocated under the lower end of the rack-bar in a lifting-jack for thepurpose of throwing the said bar up against the axle of the vehicle,after which it can be worked or forced up by the teeth of theliftinglever as desired, which saves considerable time as well asmanipulation of the lever; and it consists also in the employment or useof a detent pawl or lever for holding down the rackbar when the springis depressed.

A represents the rack-bar, which is fitted to slide up and down in a'suitable guiding` frame or case, B; and O is the lifting-lever, havingsuitable teeth for operating upon the rack-bar,

and D is a pawl or locking-lever which ts unv der the teeth ot' therack-bar and prevents the same from descending` unless said pawl isthrown out of gear for that purpose. These parts are all of well-knownconstruction, and I have mentioned them merely to give a clearerunderstanding ot' my improvements, which I will now proceed to describe.

E represents a spiral spring, which is placed Y in the bottom of thecasingB and secured therein in any suitable way, and so arranged that itwill throw up the rack-bar A, as can be understood by reference to theposition of the parts shown in red outline in Fig. 1.

F is a detent-pawl having a catch or nose, a, on its end, which catchesinto a notch, b, on the side of the rack-bar opposite the teeth when therack-bar is depressed, and a spring,

G, is applied between this pawl F and the casing, below the pivot, forthe purpose of keeping the nose bearing against the rack-bar, so that itwill catch into the notch b the moment the bar is thrust down far enoughto permit it.

H is another spring placed above the point where the locking-lever orpawl is pivoted to the ear d, which carries it as well as theliftinglever. It is so arranged as to bear against the said pawl nearits upper end for the purpose ot' keeping the same pressed against theteeth of the rack-bar, so as to hold the same at any point to which itmay be raised. By thus placing the spring it is entirely out ot' theway, (concealed, as it were,) and therefore not likely to be deranged ordamaged by careless usage of the jack.

A great advantage is gained by the employment of a spring, E, under therack-bar, namely: The jack can be set under the axle ot' the vehicle inthe desired place and the rack-bar released by pressing' upon the lowerend ot' the detent pawl orlever F, when the rack-bar will be thrown upby the force ot the spring li against the axle, which rack-bar will bedetained there by the pawl or locking-lever, and it is only necessary tomove up and down the lifting-lever two or three times and the wheel willbe snfciently elevated from the ground. This saves a great deal ot'manipulation, besides providing a more perfect and better lifting-jack.

What I claim as new, and desire to secure by Letters Patent, is-

l. The employment or use ot' a spiral spring, E, under the bottom of therack-bar, for the purposes herein shown and described.

2. The detent-pawl F, in combination with the rack-bar A and spring E,substantially as described. A

3. The combination and arrangement ofthe rack-bar A, lifting-lever O,locking bar or pawl D, spring E, detent-pawlF, and spring H, as hereinshown and described.

The above specification of my invention signed by me this 8th day ofAugust, 1865.

ALFRED VOODWORTH..

Wtnessses:

M. M. LIVINGSTON, C. L. ToPLIFF.

